Unlike contemporary advertising agencies, which work for advertisers, most agencies of the 1870s worked for publishers or acted as independent brokers between advertisers and the media. A typical agency employed a staff of five: the principal, whose name the agency bore; an estimate man who dealt with rates and expenses; a bookkeeper; a clerk; and an office boy. There were no such things as copywriters, marketing departments, or account executives. Most newspapers derived less than a third of their income from advertising. In 1870 the total revenue from newspaper advertising amounted to $16 million; by 1900 it had grown to $95 million.

A Shadowy Business.

Advertising was not regulated by the government, nor did it have a voluntary code of ethics. Publishers routinely lied about the circulations of their newspapers and magazines in order to charge higher advertising rates. Advertisements made claims that often bore little resemblance...